OpenAI doesn't allow paying ChatGPT+ subscribers to change the email address associated with an account. But this is entry level functionality for web apps. 99% of all web apps in the world allow this.
So, why do you suppose this is?
I'm currently signed up with my personal email address hello@myname.com and want to use something more anonymous. Is it possible that this is exactly the kind of thing they are trying to prevent?
I used to exploit this phenomenon to get premium campsites at a state park. Sale dates were 30 days out, but reschedules were possible up to 45. So I’d book the magic campsite early, then pay to reschedule before the sale inventory was available. There’s a million similar issues that you can find if you have a knack for it.
I have no information specific to OpenAI, but if smart people do dumb things, there’s often a reason.